Great question...I'll break it down by time of day.
SUNRISE: Point Dume Cliffs in Malibu (one of the few places on West Coast where you can see the sunrise over the ocean). Also, 1 mile up Encinal Road of PCH looking back over Zuma Beach.
MIDMORNING: Huntington Library and Gardens in San Marino.
LUNCH: Kenneth Hahn Park in Ladera Heights/Baldwin Hills looking NE at Los Angeles skyline.
MID AFTERNOON: Descanso Gardens in La Canada.
SUNSET: Mt. Wilson at Eaton Saddle (great view of the entire LA basin)
MIDNIGHT ON A FULL MOON: Surfing first point Malibu with a dozen other "friends."